In recent years, the number of pixels of a camera module which is mounted in a terminal device such as a smartphone or a mobile phone has been increasing. While a camera module has a higher resolution and the number of pixels is increased, it is not easy to reduce the cell size of an image sensor because the reception sensitivity is intended to increase.
The overall optical length required to satisfy the desired angle of view and the effective image circle diameter are in general determined to some extent, and as the number of pixels is increased, the height of the module tends to increase. In the related art, in order to reduce the overall optical length, as in the technique described in Patent Document 3, an aperture stop is disposed on the side closest to an object or between a first lens and a second lens in most configurations.
A technique disclosed in PTL 1 is an example of the related art for reducing the overall optical length. In the technique described in PTL 1, a mechanical shutter is provided on the top surface of a lens unit, and a projecting portion formed on the tip of a lens is accommodated in a recessed portion formed at the back surface of the mechanical shutter.